The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
DC-to-DC converters and linear voltage regulators typically include a zero-pole compensator circuit for stability purposes. FIG. 1 shows a traditional zero-pole compensator circuit 10 that includes a RC loop filter 12, which is connected to an output of a transconductance amplifier (voltage-to-current converter) 14. The transconductance amplifier 14 converts an input voltage to an output current I. The RC loop filter 12 includes a resistance R1 and a capacitance C1. The resistance R1 is connected in series with the capacitance C1 and filters an output voltage of the transconductance amplifier 14. Voltage across the RC loop filter 12 is identified as an output voltage Vout.
As an example, a transfer function of the zero-pole compensator circuit 10 can be represented as provided by equation 1, where Vin is the input voltage of the zero-pole compensator circuit 10, Vout is an output voltage of the zero-pole compensator circuit 10, GM is a transconductance value of the transconductance amplifier 14, s is equal to jω, j is the imaginary value √{square root over (−1)} is frequency, R1 is a value of the resistance R1, and C1 is a value of the capacitance C1.
                                          V            out                                V            in                          =                  GM          ⁡                      [                                          1                +                                  sR                  ⁢                                                                          ⁢                  1                  ⁢                  C                  ⁢                                                                          ⁢                  1                                                            s                ⁢                                                                  ⁢                C                ⁢                                                                  ⁢                1                                      ]                                              (        1        )            The RC loop filter 12 provides a single zero and a single pole. In other words, there is a single value for s that can result in the numerator of the transfer function being equal to zero and there is a single value for s that can result in the denominator of the transfer function being equal to zero.